Get Grid from Virtual Point Cloud
- Author: V. Wichmann, LASERDATA GmbH (c) 2014
- Menu: File | Virtual | Point Cloud
Description
The tool allows one to retrieve a grid from a virtual point cloud dataset by applying the provided area-of-interest (AOI). The extent of the AOI can be provided either as polygon shapefile, grid or by coordinates. Optionally, an overlap can be added to the AOI. In case an overlap is used and the AOI is provided as polygon shapfile, only the bounding boxes of the polygons are used.
With polygon shapefiles additional functionality is available:
* in case one or more polygons are selected, only the selected polygons are used.
* in case the shapefile contains several polygons a grid dataset is outputted for each polygon. In case the 'Tilename' attribute is provided, the output files are named by this attribute. Otherwise the output file names are build from the lower left coordinate of each tile.
The derived datasets can be outputted either as grid list or written to an output directory. For the latter, you must provide a valid file path with the 'Optional Output Filepath' parameter.
Optionally, the query can be constrained by providing an attribute field and a value range that must be met.
A virtual point cloud dataset is a simple XML format with the file extension .spcvf, which can be created with the 'Create Virtual Point Cloud Dataset' tool.
Parameters
| | Name | Type | Identifier | Description | Constraints |
|---|
| Input | Shape | shapes, input, optional | AOI_SHP | Shapefile describing the AOI. | - |
| Grid | grid, input, optional | AOI_GRID | Grid describing the AOI. | - |
| Output | Grid | grid list, output, optional | GRID_OUT | The output grid(s) | - |
| Options | Filename | file path | FILENAME | The full path and name of the .spcvf file | - |
| Optional Output Filepath | file path | FILEPATH | The full path to which the output(s) should be written. Leave empty to output the datasets as grid list. | - |
| Attribute Field to Grid | integer number | ATTR_FIELD_GRID | The attribute field to grid. Field numbers start with 1, so elevation is attribute field 3. | Minimum: 3
Default: 1 |
| Cellsize | floating point number | CELL_SIZE | Cellsize of the output grid [map units] | Minimum: 0.001000
Default: 1.000000 |
| Grid System Fit | choice | GRID_SYSTEM_FIT | Choose how to align the ouput grid system to the AOI | Available Choices:
[0] nodes
[1] cells
Default: 1 |
| Aggregation | choice | METHOD | Choose how to aggregate the values | Available Choices:
[0] lowest
[1] highest
Default: 1 |
| Constrain Query | boolean | CONSTRAIN_QUERY | Check this parameter to constrain the query by an attribute range. | Default: 0 |
| Attribute Field | integer number | ATTR_FIELD | The attribute field to use as constraint. Field numbers start with 1. | Minimum: 1
Default: 1 |
| Value Range | value range | VALUE_RANGE | Minimum and maximum of attribute range []. | - |
| Tilename | table field | FIELD_TILENAME | Attribute used for naming the output file(s) | - |
| Grid system | grid system | AOI_GRID_GRIDSYSTEM | - | - |
| X-Extent | value range | AOI_XRANGE | Minimum and maximum x-coordinate of AOI. | - |
| Y-Extent | value range | AOI_YRANGE | Minimum and maximum y-coordinate of AOI. | - |
| Add Overlap | boolean | AOI_ADD_OVERLAP | Add overlap to AOI | Default: 0 |
| Overlap | floating point number | OVERLAP | Overlap [map units] | Minimum: 0.000000
Default: 50.000000 |
Command Line
Usage: saga_cmd io_virtual 4 [-FILENAME ] [-GRID_OUT ] [-FILEPATH ] [-ATTR_FIELD_GRID ] [-CELL_SIZE ] [-GRID_SYSTEM_FIT ] [-METHOD ] [-CONSTRAIN_QUERY ] [-ATTR_FIELD ] [-VALUE_RANGE_MIN ] [-VALUE_RANGE_MAX ] [-AOI_SHP ] [-FIELD_TILENAME ] [-AOI_GRID ] [-AOI_XRANGE_MIN ] [-AOI_XRANGE_MAX ] [-AOI_YRANGE_MIN ] [-AOI_YRANGE_MAX ] [-AOI_ADD_OVERLAP ] [-OVERLAP ]
-FILENAME: Filename
file path
-GRID_OUT: Grid
grid list, output, optional
-FILEPATH: Optional Output Filepath
file path
-ATTR_FIELD_GRID: Attribute Field to Grid
integer number
Minimum: 3
Default: 1
-CELL_SIZE: Cellsize
floating point number
Minimum: 0.001000
Default: 1.000000
-GRID_SYSTEM_FIT: Grid System Fit
choice
Available Choices:
[0] nodes
[1] cells
Default: 1
-METHOD: Aggregation
choice
Available Choices:
[0] lowest
[1] highest
Default: 1
-CONSTRAIN_QUERY: Constrain Query
boolean
Default: 0
-ATTR_FIELD: Attribute Field
integer number
Minimum: 1
Default: 1
-VALUE_RANGE_MIN: Value Range
value range
-VALUE_RANGE_MAX: Value Range
value range
-AOI_SHP: Shape
shapes, input, optional
-FIELD_TILENAME: Tilename
table field
-AOI_GRID: Grid
grid, input, optional
-AOI_XRANGE_MIN: X-Extent
value range
-AOI_XRANGE_MAX: X-Extent
value range
-AOI_YRANGE_MIN: Y-Extent
value range
-AOI_YRANGE_MAX: Y-Extent
value range
-AOI_ADD_OVERLAP: Add Overlap
boolean
Default: 0
-OVERLAP: Overlap
floating point number
Minimum: 0.000000
Default: 50.000000